According to reviews and my own experience, the 50/1.4 is the bargain of the bunch. At f/2.8 and further, it's as sharp or sharper, it's almost as bright as the 50/1.2L. The 50/1.8 really isn't a very sharp lens.

It is a great lens, I like it a lot. Great indoors with low light. I have not used the 1.4 or 1.8, so I cannot compare directly, though I have looked at the 1.4 as a friend of mine has it and it is what made me want to get the 1.2. The quality of the lens is superb. The build quality is excellent, better than some of my other L lenses. Is it worth 600 extra? I do not regret paying what I paid for it one bit, so I think it is worth the extra.

Not sure how practical it is to use at f1.2 with the shallow DOF. You can get some really nice effects and really highlight the part of the subject you want to see most, though the focus needs to be spot on. It does focus well in low light, which is to be expected with such a wide aperture.

What I like is that it seems to let in more light at F4.0 than my 24-105 F4.0 IS USM L lens. I found I gained a stop in ISO when I compared the 2 lenses.

It is going to be perfect for my brother's wedding later in the year. I should also be much better at getting the best out of it by then too:)

Just got this lens yesterday, first conclusion: This lens is very difficult to use. The shallowdepth of field leaves no room for errors. After taking almost 100 pictures I found only a few of them useable.
Also, this lens seems to hunt in lowlight more than my 24-70 2.8 L, which is somewhat of a letdown. Afterall one would buy this for lowlight situations.
The 50mm F/1.2 L is softer at 1.2 than my 24-70L at 2.8, at 2.8 its a lot sharper.

Here are some pictures, still getting used to that shallowdepth of field, this lens can be fun to use. But also very frustrating.

_________________http://www.AnderssonPhoto.com Equipment: A blend of Canon, Nikon, Yashica, Leica, Voigtlander, Samyang and Sigma. All of which you can see on my website!Wishlist: Leica M 240, Summilux 50 ASPH, Summilux 24 ASPH

I have been wondering about this as well and have not found sufficient evidence that it is. Although I would very much like to have a "showdown" in the lens section if anyone is interested, it must be with the same type of body/camera.

Yes this lens is bokelicous! And I like to use it with a 7D a lot. I hardly use my 24-70 2.8 L anymore, just because of how beautiful pictures turn out when I use the 50mm 1.2 L.
And besides, I usually used the 24-70 2.8L around 70mm anyways!

I hope to upgrade my camera body sometime in the future to something like a 5D mark III! That would be result in even more bokeh!